1. Field of the Invention
The present invention relates generally, as is indicated, to an integrated circuit card, hereinafter referred to as an IC card, with a built-in voice synthesizing function. More particularly, the present invention relates to an IC card with a built in voice synthesizing function that is capable of reconstructing voice signals from vector-quantized coded data for production of voice messages and the like.
2. Description of the Prior Art
In the past, to produce voice messages such as a reading of a novel, etc. on an electronic apparatus, it has been necessary, as shown in FIG. 2, to load a magnetic tape 11 with original voice signals recorded thereon into a magnetic tape reproducing apparatus 12 for reproducing the original voice signals.
With the magnetic tape reproducing apparatus 12, however, it is difficult to reduce the size and weight of the apparatus because of the complex mechanism for replaying the magnetic tape 11. Also, there is a limit to the reduction in the size of the magnetic tape 11 itself. Furthermore, since recorded information cannot be randomly accessed, the magnetic tape 11 must be fast-forwarded or rewound to replay the recorded information from the desired position or to return to the starting point of the recording.
As a result, the conventional magnetic tape reproducing apparatus 12 has had the problem that the apparatus not only takes space and hampers portability because of its size but also requires a cumbersome and time-consuming procedure for operation.
Another known method of voice reproduction is by reconstructing the original signal from vector-quantized coded data using a code book.
However, with the method of reproducing voice from vector-quantized coded data, although the device can be constructed entirely from simple electronic circuits, it requires the use of a large-capacity ROM for the code book.
As a result, the conventional voice reproducing device based on vector quantization has had the problem that the provision of a large-capacity ROM makes it difficult to build-in the device into an IC card; making the ROM capacity smaller than necessary would result in degradation in the voice reproduction quality.
In view of the above problems, there is a strong need in the art for an inexpensive, compact, light-weight, and easy-to-operate IC card with a built-in voice synthesizing function, in which vector-quantized coded data is decoded using patterns generated by a recurrence equation such as a pseudo-random sequence.
Accordingly, the present invention overcomes the aforementioned short comings of the above known and similar devices and methods for providing a voice synthesizing function. The present invention is summarized and described in detail below.